Where to set timing!
 

Background on the truck.
5x18 injectors
full cut dv
normal head parts
215 pump 4k gsk set tight.
nv4500 pulling in 2nd high with 4.10 gears
comp puller clutch
other odds and ends.


Have searched and have come up empty handed with the issue I am having. We were having issues with not spinning out with a S472 with the smallest t4 housing they have for it. Recently added a adj timing gear and billet cover and set the timing to 28* (from 18*) and the truck did NOT like it at all. Snuffed the charger on the line (2 attempts). Now looking for a few more suggestions of where and why to set the timing at. Truck carries 3600rpm down the track right up until it snuffs.

Thanks in advance.
Thanks to the members I have already talked to via phone.

What IC set up are you running, or size tires, and what size is turbine wheel? That's a pretty fast gear to try and run with out motor to back it imo. The needed timing depends on injector spray pattern and bowl style as well.

2nd high Is a tall gear , to spin out at the end with a s400 with stock bowl Pistons . more than 25 degrees timing won't help with stock bowl pistons . Sounds like you need 5.13 gears and pull 4th low

Change your gears and pull in direct 4th low

Gear change may be coming this winter but for the few pulls we have left I'm just trying to make it work. We have run 4th low and 2nd high back to back on same day,sled,track. only gained 9ft more by dropping to 2nd high and 3rd low is not an option. Running six 285/75/16 bfg at. Its not a hard violent snuff out at the end of the track. It reminds me a lot of a farm tractor using every oz oh hp and eventually just shutting off.

I'd back the timing down to 24-25*.

A box stock s400 will snuff on most engines ..

Would it stay on top of a modified s400 or gt42 better than box stock 475?

We spun out with 410 gear 33's and a 75 mm turbo on a t6 housing at 22 degrees maxed out 215 pump watch egts maybe to much fuel

We spin out with 35" old style BFGs 4:10s and a 2.5 inducer S400 in 4 low 4th. We used to snuff out at the end when we had a fueling issue. 5x18 injectors are not enough for that turbo pulling IMO. 5x18s were not enough for us. We run 5x22 JL injectors now on our 2.5 and that is about perfect for our setup. Run too small of an injector and heat will be an issue. Ours cooled way down and quit snuffing. Carries 80 psi until we let out. A tight housing on a small turbine isn't the best setup in itself.

Does a bigger turbine help stay on top of it? I've heard the inertia of the big turbine helps.

Say like a 3x3 vs 3x3.6 vs 3x4